Accepted Answer

Hey XXXXXXXX thanks for the question on your BMW,

It sounds like you have ruled out the fuel lines and fuel pressure regulator, return fuel lines. I do not see any mention of the car running bad or stalling when this happens, so I assume it runs fine. You do mention the leak in the front of the vehicle, and in the left front of the engine compartment there is the charcoal cannister for the emission controls mounted just to the left of the power steering resevoir. The charcoal cannister is designed to absorb fumes from the fuel separator in the right rear wheel well near the gas tank filler neck, that vents from the fuel tank, I am thinking that I would look at the bottom of the charcoal cannister to see if there is any sign of fuel there. The cannister is suppose to be protected by valves and other devices, but I suppose there is the chance that raw fuel somehow gets past the valve, fills the line and finally spits out some fuel, all while runing normal. The problem maybe the fuel separator, in back right wheel well by filler neck, and not the charcoal cannister itself. Might be worth a look, I personally have not heard of this problem, but sometimes with cars, you never say never.

If this helps, please accept, if not let me know, all bonuses and feedback appreciated.
Thanks,